i) We are told to differentiate the expression for Q.
Power rule of derivation:
The given expression is:
For RC circuit shown here, Kirchhoff's voltage loop rule would result in V0 – IR – Q/C = 0. If the capacitor initially has a charge Q0 on it at time 0 (it is partially pre-charged), the charge on it at later times is given by Q = V0C(1 – e-t/RC) + Q0e-t/Rc. This expression is a combination of the capacitor both charging and discharging simultaneously.
i) Find the current in the circuit by differentiating the above expression for charge.
ii) Show that with the expressions for charge as given in the statement of the problem, and the current that you found in part i), that Kirchhoffs loop equation [V0 – IR – Q/C = 0] is satisfied.
Frequently Asked Questions
What scientific concept do you need to know in order to solve this problem?
Our tutors have indicated that to solve this problem you will need to apply the Kirchhoff's Loop Rule concept. You can view video lessons to learn Kirchhoff's Loop Rule. Or if you need more Kirchhoff's Loop Rule practice, you can also practice Kirchhoff's Loop Rule practice problems.